A simple pendulum is suspended from the roof of a train. If the train is moving with an acceleration of 49 cm/s^{2} , then the angle of inclination of the string about the vertical will be ____.
a) 20°
b) 0°
c) 30°
d) 3°
pseudo force=ma
gravity=mg
tan\(\theta = {ma\over mg }\)
\(\theta = tan^{-1}({ma\over mg})\)
\(=tan^{-1}({ 0.49\over 9.8})\)
\(=tan^{-1}(0.05)\)
=\(3 ^o\)